Histone post-translational modification (PTM) antibodies are essential research reagents in chromatin biology. However, they suffer from variable properties and insufficient documentation of quality. Antibody manufacturers and vendors should provide detailed lot-specific documentation of quality, rendering further quality checks by end-customers unnecessary. A shift from polyclonal antibodies t...

Every regulator should be regulated, and this holds true for small RNAs and their associated proteins. Knowledge has begun to emerge of the various mechanisms that impose specificity on the expression and function of RNA silencing factors. Recent papers, including one in this issue of Cell (Paroo et al., 2009), now reveal the posttranslational modifications that take part in the regulation of t...

OGlcNAcylation and phosphorylation are the major competing intracellular post-translational modifications of serine and threonine residues. The structural effects of both post-translational modifications on serine and threonine were examined within Baldwin model α-helical peptides (Ac-AKAAAAKAAAAKAAGY-NH2 or Ac-YGAKAAAAKAAAAKAA-NH2). At the N-terminus of an α-helix, both phosphorylation and OGl...

Leukocytes undergo frequent phenotypic changes and rapidly infiltrate peripheral and lymphoid tissues in order to carry out immune responses. The recruitment of circulating leukocytes into inflamed tissues depends on integrin-mediated tethering and rolling of these cells on the vascular endothelium, followed by transmigration into the tissues. This dynamic process of migration requires the coor...

Integration of inorganic sulfate into biological molecules plays an important role in biological systems and is directly involved in the instigation of diseases. Protein tyrosine sulfation (PTS) is a common post-translational modification that was first reported in the literature fifty years ago. However, the significance of PTS under physiological conditions and its link to diseases have just ...

Post-translational modifications (PTMs) of proteins play essential roles in almost all cellular processes, and are closely related to physiological activity and disease development of living organisms. The development of tandem mass spectrometry (MS/MS) has resulted in a rapid increase of PTMs identified on proteins from different species. The collection and systematic ordering of PTM data shou...

We present a generic analytical scheme for the quantification of fluctuations due to bifunctionality-induced signal transduction within the members of a bacterial two-component system. The proposed model takes into account post-translational modifications in terms of elementary phosphotransfer kinetics. Sources of fluctuations due to autophosphorylation, kinase, and phosphatase activity of the ...

In vitro phosphorylation of purified human plasma apolipoprotein A-I (apoA-I) by a recently characterized Ca2+/calmodulin-dependent kinase (Beg, Z. H., Stonik, J. A., and Brewer, H. B., Jr. (1987) J. Biol. Chem. 262, 13228-13240) was time-, Ca2+-, and calmodulin-dependent. Maximal phosphorylation of human apoA-I revealed a stoichiometry of approximately 1 mol of PO4/mol of apoA-I. Phosphorylati...

Terpenes are ubiquitous natural chemicals with diverse biological functions spanning all three domains of life. In specialized metabolism, the active sites of terpene synthases (TPSs) evolve in shape and reactivity to direct the biosynthesis of a myriad of chemotypes for organismal fitness. As most terpene biosynthesis mechanistically involves highly reactive carbocationic intermediates, the pr...

Post-translational modifications of histones play crucial roles in the genetic and epigenetic regulation of gene expression from chromatin. Studies in mammals and yeast have found conserved modifications at some residues of histones as well as non-conserved modifications at some other sites. Although plants have been excellent systems to study epigenetic regulation, and histone modifications ar...